Helm Common library

The common library is a way to unify the UX through all the Helm charts that implement it.

The tooling suite that New Relic is huge and growing and this allows to set things globally and locally for a single chart.

Documentation for chart writers

If you are writing a chart that is going to use this library you can check the developers guide to see all the functions/templates that we have implemented, what they do and how to use them.

Values managed globally

We want to have a seamless experience through all the charts so we created this library that tries to standardize the behaviour of all the charts. Sadly, because of the complexity of all these integrations, not all the charts behave exactly as expected.

An example is newrelic-infrastructure that ignores hostNetwork in the control plane scraper because most of the users has the control plane listening in the node to localhost.

For each chart that has a special behavior (or further information of the behavior) there is a "chart particularities" section in its README.md that explains which is the expected behavior.

At the time of writing this, all the charts from nri-bundle except newrelic-logging and synthetics-minion implements this library and honors global options as described in this document.

Here is a list of global options:

Global keys	Local keys	Default	Merged1	Description
global.cluster	cluster	""		Name of the Kubernetes cluster monitored
global.licenseKey	licenseKey	""		This set this license key to use
global.customSecretName	customSecretName	""		In case you don't want to have the license key in you values, this allows you to point to a user created secret to get the key from there
global.customSecretLicenseKey	customSecretLicenseKey	""		In case you don't want to have the license key in you values, this allows you to point to which secret key is the license key located
global.podLabels	podLabels	{}	yes	Additional labels for chart pods
global.labels	labels	{}	yes	Additional labels for chart objects
global.priorityClassName	priorityClassName	""		Sets pod's priorityClassName
global.hostNetwork	hostNetwork	false		Sets pod's hostNetwork
global.dnsConfig	dnsConfig	{}		Sets pod's dnsConfig
global.images.registry	See Further information	""		Changes the registry where to get the images. Useful when there is an internal image cache/proxy
global.images.pullSecrets	See Further information	[]	yes	Set secrets to be able to fetch images
global.podSecurityContext	podSecurityContext	{}		Sets security context (at pod level)
global.containerSecurityContext	containerSecurityContext	{}		Sets security context (at container level)
global.affinity	affinity	{}		Sets pod/node affinities
global.nodeSelector	nodeSelector	{}		Sets pod's node selector
global.tolerations	tolerations	[]		Sets pod's tolerations to node taints
global.serviceAccount.create	serviceAccount.create	true		Configures if the service account should be created or not
global.serviceAccount.name	serviceAccount.name	name of the release		Change the name of the service account. This is honored if you disable on this cahrt the creation of the service account so you can use your own.
global.serviceAccount.annotations	serviceAccount.annotations	{}	yes	Add these annotations to the service account we create
global.customAttributes	customAttributes	{}		Adds extra attributes to the cluster and all the metrics emitted to the backend
global.fedramp	fedramp	false		Enables FedRAMP
global.lowDataMode	lowDataMode	false		Reduces number of metrics sent in order to reduce costs
global.privileged	privileged	Depends on the chart		In each integration it has different behavior. See Further information but all aims to send less metrics to the backend to try to save costs
global.proxy	proxy	""		Configures the integration to send all HTTP/HTTPS request through the proxy in that URL. The URL should have a standard format like https://user:password@hostname:port
global.nrStaging	nrStaging	false		Send the metrics to the staging backend. Requires a valid staging license key
global.verboseLog	verboseLog	false		Sets the debug/trace logs to this integration or all integrations if it is set globally

Further information

1. Merged

Merged means that the values from global are not replaced by the local ones. Think in this example:

global:
  labels:
    global: global
  hostNetwork: true
  nodeSelector:
    global: global

labels:
  local: local
nodeSelector:
  local: local
hostNetwork: false

This values will template hostNetwork to false, a map of labels { "global": "global", "local": "local" } and a nodeSelector with { "local": "local" }.

As Helm by default merges all the maps it could be confusing that we have two behaviors (merging labels and replacing nodeSelector) the values from global to local. This is the rationale behind this:

• hostNetwork is templated to false because is overriding the value defined globally.
• labels are merged because the user may want to label all the New Relic pods at once and label other solution pods differently for clarity' sake.
• nodeSelector does not merge as labels because could make it harder to overwrite/delete a selector that comes from global because of the logic that Helm follows merging maps.

2. Fine grain registries

Some charts only have 1 image while others that can have 2 or more images. The local path for the registry can change depending on the chart itself.

As this is mostly unique per helm chart, you should take a look to the chart's values table (or directly to the values.yaml file to see all the images that you can change.

This should only be needed if you have an advanced setup that forces you to have granularity enough to force a proxy/cache registry per integration.

3. Privileged mode

By default, from the common library, the privileged mode is set to false. But most of the helm charts require this to be true to fetch more metrics so could see a true in some charts. The consequences of the privileged mode differ from one chart to another so for each chart that honors the privileged mode toggle should be a section in the README explaining which is the behavior with it enabled or disabled.